It is a simple question, but there are only fragments of an answer. The question is: Why do so many Muslims, born in Britain, turn to jihadism?

The best numbers available show that more than 500 young, British-born Muslims have traveled to Syria to fight for the Islamic State. By comparison, an estimated 100 Americans have taken up arms for the Islamic State. As the population of the United States is 313 million, compared to 63 million for the whole of Britain, the disparity is huge.

The “the enemy within,” as the British media calls these young people, has deeply disturbed the British public, as it looks to its political leaders to take action. One writer, in The Daily Telegraph, says that the government has been soft when it should have been tough, and tough when it should have been soft.

The truth is that successive British administrations have been silent on the consequences of immigration since the second Churchill government in the 1950s. Everyone is to blame and no one is to blame.

Britain never saw a large influx of immigrants after the Norman Conquest in 1066. In fact, it had become quite proud of its tolerance for émigrés; Karl Marx was the exemplar. The Jews were tolerated after the 1650s, but excluded from many occupations and social circles.

Past and present Britain is made up of enclaves remarkably disinterested in each other. Hence, a small island nation can support 53 distinct, regional accents and dialects.

Idealists believed that post-World War II immigration would change Britain for the better, sweep away its imperial trappings. Actually if anything eroded the class structure, it was the great wave of pop music and fashion in the 1960s.

Surveys show that of the immigrants from the subcontinent, the Indians assimilated best and took to business — and the class system — with alacrity, many becoming millionaires. The Muslims, primarily from Pakistan, have fared the worst. They assimilated least and imported practices that are a savage affront to British values: forced and under-age marriages, honor killings, and halal butchers, opposed by many British animal rights groups.

These same values have made life rough for young men of Pakistani descent. For working-class British youth, sex, booze, music and soccer are their safety valves. Sexual frustration is endemic all over the Muslim world; it is at work among devout, young Muslim men in Britain, where sex is celebrated in the culture.

British business had a role in the mix of immigrants in the 1960s. Businesses wanted workers for the textile mills and factories in northern England, who would do the dirty, poorly paid work nobody else wanted. The proprietor of large tire retreading company boasted to me in 1961 how he had solved the labor problem by recruiting rural Pakistanis, who worked hard and cheaply and kept to themselves. His words have echoed with me down through the years.

This alone does not explain why, for example, a preponderance of the jihadists are from London, or why some of them seem to be university types from the London School of Economics, King’s College London, the School for Oriental and African Studies, and others. If you are young, male and Muslim, and even somewhat religious, it is easy to be persuaded that you live among the infidels with their alcohol and preoccupation with coitus.

But, again, it is not explanation enough; not an explanation of why a generation of British-born young men are attracted to the life and values of their distant ancestors, or why they have shown such savagery.

Britain has comforted itself by dealing with self-identified “community leaders” in the Muslim community. Unfortunately the real leaders have been fiery, foreign-born imams who proselytize hatred in the mosques that serve Britain’s 2 million Muslims. The Muslim communities have been hidden in plain sight from the British mainstream.  — For the Hearst-New York Times Syndicate